Oil well derrick and method of erection



1950 H. J. WOOLSLAYER ETAL 2,963,124

OIL WELL DERRICK AND METHOD OF ERECTION Filed July :50, 1957 s Sheets-Sheet 1 30 INVENTORS Wal fl -ronnfys 1960 H. J. WOOLSLAYER ET AL 2,953,124

I OIL WELL DERRICK AND METHOD OF ERECTION Filed July 30, 1957 3 Sheets-Sheet 2 '1 '1 1 l l i i 22 20 l I L. 1 l 1 H I 22"" l Ii /20 l h l 1 I I I u 22 I I I} I l T'l h m a l "1 h I I l zl lilj 7 L-m "5" 21 l r22 22 32 r HM I? J. Wi 23 24 3/ E: 23 AND CECIL J'EN INS 27 F n BY 6M, M+

Dec. 6, 1960 Filed July 30, 1957 H. J. WOOLSLAYER ETAL 2,963,124

OIL wzu. DERRICK AND METHOD OF ERECTION 3 Sheets-Sheet 3 INVENTORS HOMER .1 waazsmysk CECIL JEN/(INS United States Patent OIL WELL DERRICK AND METHOD OF ERECTION Filed July 30, 1957, Ser. No. 675,081

6 Claims. (Cl. 18915) This invention relates to oil well derrick structures,

and to a method of raising and lowering the mast that forms part of such a structure.

For many years it has been common practice to erect oil well drilling masts by first assembling them along the ground and then swinging them up to upright position by means of the tackle used in the drilling operations. This tackle includes the crown block, the traveling block and the line that connects them together and to the drawworks. In raising such a mast, the traveling block is hooked onto an erection line that extends out of the lower part of the mast and up to the head of the gin pole located behind the mast. For short masts the erection line or sling is fastened directly to the gin pole, but for taller and heavier masts the sling extends around sheaves supported by the pole and then is anchored to the upper side of the reclining mast to provide -a twoline string-up. When the traveling blockis drawn toward the head of the reclining mast, the sling swings the mast up to upright position.

For deep drilling, the masts have to be very tall and strong, and therefore they are very heavy. To raise them in the manner just described requires slinglines of inconveniently large diameter beyond the range of sizes commonly stocked by manufacturers. It is known that the erection stresses in the structure could be reduced and slinglines of smaller sizes used if they could be strung up in such a manner as to use more lines than the usual two that now are formed by a sling extending from the mast back around gin pole sheaves and then forward to ;the mast again. Nevertheless, more than a double line string-up has not been used heretofore, because even such a string-up requires the traveling block to travel to practically the head of the mast before the mast will reach upright position. If, instead of anchoring the sling at themast, it were also passed around sheaves on the back of the mast and then anchored at the gin pole to form a three-line string-up, the traveling block would have to travel still farther. Since there is no more space available in the mast, that would be impossible. It is not economical to increase the mast height merely for erection purposes. Even in the case of short masts when a single-line string-up has been used, it would be advantageousin some cases to be able to use a double-line string-up if thatwere possible.

It is among the objects of this invention to provide an oil well drilling structure in which the lines of the sling string-up can be increased over what has been possible heretofore, and in which the eliective travel distance of the traveling block during raising or lowering of a mast is unlimited.

In accordance with this invention the erection line is strung up in. such a way that the traveling block connected to it will reach its upper limit of travel before the mast has, been swung fully upright. The mast is then I supported in inclined position by independent means,

such as a detachable link connecting to it the top of the Patented Dec. 6, 1960 2 gin pole, while the traveling block is returned to lower part of the mast. To prevent the block from dropping out of the open front of the mast as the block is lowered, it may be supported by a carriage running lengthwise of the inside of the mast. After the traveling block has been returned to the lower part of the mast, the erection line between the gin pole and point of attachment to the block is shortened. The traveling block then is pulled toward the head of the mast again to cause the shortened erection line to raise the inclined mast further toward upright position beside the gin pole.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which Fig. 1 is a side view of a reclining mast ready to be raised;

Fig. 2 is a side view showing the mast raised to inclined position, with the traveling block at its upper limit of travel;

Fig. 3 is a similar view showing the inclined rnast supported by the gin pole and the traveling block prepared to raise the mast further;

Fig. 4 is a side view showing the mast fully erected;

Fig. 5 is an enlarged transverse section of the mast, taken on the line V-V of Fig. 2;

Fig. 6 is a further enlarged plan view of the carriage for the traveling block;

Figs. 7 and 8 are sections through the carriage, taken on the lines VIIVII and VIII-VIII, respectively;

Fig. 9 is an enlarged detail of Fig. 3, showing link 12 connecting the mast to the gin pole; and

Fig. 10 is an enlarged detail showing the slingline rigging as viewed from above in Fig. 1.

Referring to Fig. l of the drawings, the usual gin pole 1 is mounted on a substructure or baseZ of any suitable construction. Hinged to the base directly in front of the gin pole is the foot of a reclining mast 3 that extends forward along the ground. The mast is formed from prefabricated sections that have been assembled in the reclining position. The lower or front side of the reclining mast is open, as is customary. Mounted on the base behind the gin pole is the usual drawworks 4, which is connected by a drilling line 5 with the crown block 6 at the head of the mast and the traveling block 7 inside of'the mast.

To raise the mast, the traveling block is hooked onto the lower end of an erection line. This line is generally in the form of a bridle sling 8, the central portion of which is connected to the traveling block. From that point, the slingline extends backward beneath sheaves 9 in the lower part of the mast and then up and around sheaves 10 supported by the head of the gin pole. From there the sling extends forward above the mast. To increase the mechanical advantage and reduce the necessary diameter of the slingline, the sling preferably is not anchored to the mast but extends around a pair of sheaves 11 supported by the upper side of the reclining mast and then extends back to the head of the gin pole, where it is anchored.

This gives a three-line string-up for the sling, but it will be seen that more lines can be provided by using more sheaves and a longer slingline. It also will be seen that for every foot the slingline is shortened between gin pole sheaves 10 and upper mast sheaves 11, the traveling block moves three feet nearer to the crown block. The result is that the traveling block will reach the head of the mast long before the mast is upright; that is, while it is still in inclined position as shown in Fig. 2.

Itis a feature of this invention that the inclined mast then independently supported while the traveling block is moved back downthrough the mast in preparation for another trip up the mast pulling a shortened slingline that will swing the mast the rest of the way up. Accordingly, after the traveling block reaches the head of the inclined mast, the mast is temporarily supported by suitable means, preferably .by a pair ofrigid or flexible links 12 (Fig. 3) detachably connected to'the'heefof the mast and either. pivotally or detachably connected to the head of the gin pole. These links are strong enough to hold the mast when the tensio'nion the slingline is relieved. The traveling block'then is lowered in the mast to its original lower position or thereabouts, and the slingline is shortened so that the mast will again be supported by it when the links are removed, even though the traveling block new is near the'lower end of the mast. When the traveling block is pulled toward the head of the mast again, the shortened sling Will swing the mast the rest of the way up to upright position against the gin pole, as shown in Fig. 4. Of course, it will be understood that if more than a three-line string-up of the sling is used, it may be necessary to support the mast temporarily in two different inclined positions while the sling is shortened twice.

The sling may, be shortened in various ways] One .Way is to remove the sling entirely while the inclined mast is being supported by the links 12 and to replace it with a shorter sling. Another manner of shortening the slingline is to disconnect one end of the line from the gin pole and pull it to take up the slack in the line as the traveling block is lowered in the inclined mast. When the block reaches its lower position, the intermediate-portion of the slingline engaging the gin pole is clamped to it. A third arrangement is to use a slingline that is formed in three sections detachably connected together in any suitable manner, such as by pins 13 extending through clevises 14 attached to the opposite ends of the center section 15 and through suitable loops or eyes attached to the two end sections 16. To avoid the complication of having the clevises travel around the sling sheaves, the two end sections of the slingiine are of such length that the clevises will not quite reach the sheaves 11 on the back of the mast when it is in its temporary inclined position. These two end sections are removed from the rest of the slingline while the mast is supported from the gin pole by the links, and then the clevises at the opposite ends of the middle section of the slingline are secured to the head of the gin pole, resulting in a shortened slingline.

When the slingline is shortened in the second manner described in the preceding paragraph, wherein the slingline can be maintained under tension, it can be used to prevent the traveling block from descending straight down from the crown block as the drilling line is payed out for the purpose of permitting the traveling block to return to the lower part of the mast. However, the other described methods of shortening the slingline require the tension on it to be released, so other means must be provided for holding the traveling block in the inclined mast as it is lowered therein. For this purpose, it is preferred to use a dolly or carriage that supports the traveling block and travels down through the mast.

The carriage, as shown in Figs. 6, 7 and 8, preferably is a simple rectangular frame 20 having rollers 21 mounted on its four corners. These rollers rest on parallel rails 22 formed from angle bars secured to the inner or lower surface of the upper or rear side of the inclined mast and extending lengthwise thereof to form a track. The rollers may be prevented from rising off the track by means of brackets 23 secured to the sides of the carriage frame and projecting laterally beneath the rails substantially in sliding engagement with them. The carriage normally is held near the head of the mast by a removable pin 24 extending through aligned holes in overlapping tongues 25 and 26 fastened, respectively, to the upper end of the carriage and to one of the back cross braces 27 of the mast.

To attach the traveling block to the carriage, two or more cables 30 are used that extend beneath the block and up its sides, with their ends attached to the carriage frame, as shown in Figs. 2' and 5. One end of each cable may be permanently connected to the frame, while the other end is provided with a clevis 31, through which a removable pin 32 extends for connecting it to the opposite side of the frame. As shown in Fig. 2, the traveling block is lashed to the'carriage by these cables before the tension on the drilling line is released, and then pin 24 is removed and the drilling line can be payed out to permit the carriage to roll down the mast track with the block suspended from it inside the mast. After the slingline has been shortened, the lowered traveling block can be released from the carriage, as shown in Fig. 3, and the carriage left at the lower end of the mast while the block is pulled up through the mast again to swing it into upright position. The carriage then will be in the right location when the mast is lowered again.

To lower the mast, the elevated traveling block is hooked onto the shortened slingline, and the mast then is allowed to swing out to inclined position as the block is lowered. After the inclined mast has been connected to the top of the gin pole by the links 12, the traveling block is connected to thecarriage and then the slingline is lengthened to permit the block to be pulled to the upper end of the mast to tighten the slingline. The mast then is released from the gin pole and lowered to the ground by means of the longer sling as the traveling block again moves toward the lower end of the mast.

There may be cases where the traveling block can be left connected to the carriage while the block is raising or lowering the mast, although probably nothing would be gained by doing so unless the slingline had to be shortened or lengthened twice during the raising or lowering operation.

With this invention, any length slingline desired can be used, whereby a multiple line string-up of several lines is possible. According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. In an oil well derrick structure, the combination with a base, a gin pole mounted thereon, a reclining mast hinged to the base beside the gin pole and extending away from it along the ground, a traveling block in the lower part of the mast, an erection line connected with the top of the gin pole and extending into the lower part of the mast and connected to the traveling block, and means for pulling the traveling block toward the head of the mast to cause the erection line to tilt the mast up to a'predetermined inclined position, of means supporting the mast in said inclined position while the traveling block is returned to the lower part of the mast, and means for shortening the length of erection line between the gin pole and the point of attachment of the line to the returned traveling block, whereby the mast can be raised further toward upright position beside the gin pole by pulling the traveling block toward the head of the mast again after removal of said supporting means.

2. In an oil well derrick structure as recited in claim 1, said supportingmeans comprising a link detachably connecting the inclined mast with the upper part of the gin pole.

3. In an oil well derrick structure, the combination with a base, a gin pole mo'untedthereon, a reclining mast hinged to the base beside the gin pole and extending away from it along the ground, a traveling block in the lower part of the mast, erection line connected with the top of the gin pole and extending into the lower part of the mast and connected to the traveling block, and means for pulling the traveling block toward the head of the mast to cause the erection line to tilt the mast up to a predetermined inclined position, of means supporting the mast in said inclined position, a carriage suspended from the upper side of the inclined mast and movable lengthwise of the mast, and means detachably connecting the traveling block to said carriage to support the traveling block so that it can be returned to the lower part of the mast, and means for shortening the length of erection line between the gin pole and the point of attachment of the line to the returned traveling block, whereby the mast can be raised further toward upright position beside the gin pole by pulling the traveling block toward the head of the mast again after removal of said supporting means.

4. In an oil well derrick structure, the combination with a base, a gin pole mounted thereon, a reclining mast hinged to the base beside the gin pole and extending away from it along the ground, a traveling block in the lower part of the mast, an erection line connected with the top of the gin pole and extending into the lower part of the mast and connected to the traveling block, and means for pulling the traveling block toward the head of the mast to cause the erection line to tilt the mast up to a predetermined inclined position, of means supporting the mast in said inclined position, tracks extending lengthwise along the lower surface of the upper side of the inclined mast, a carriage movable along the tracks, means detachably suspending the traveling block from said carriage for return to the lower part of the mast, and means for shortening the length of erection line between the gin pole and the point of attachment of the line to the returned traveling block, whereby the mast can be raised further toward upright position beside the gin pole'by pulling the traveling block toward the head of the mast again after removal of said supporting means.

5. In an oil well derrick structure, the combination with a base, a gin pole mounted thereon, a reclining mast hinged to the base beside the gin pole and extending away from it along the ground, a traveling block in the lower part of the mast, means for pulling the traveling block toward the head of the mast, and a pair of sheaves mounted in the upper part of the gin pole, of a pair of sheaves carried by the upper side of the reclining mast, a slingline having its ends secured to the upper part of the gin pole, the slingline extending around said mast sheaves and then back around said gin pole sheaves and then into the lower part of the mast to connection with the traveling block, the slingline being of such length that the traveling block is close to the head of the mast when the slingline has raised the mast to -a predetermined inclined position, means temporarily connecting the mast to the upper part of the gin pole while the mast is in said inclined position to permit the traveling block to be returned tothe lower part of the mast, and means for shortening the length of slingline between the gin pole sheaves and its point of attachment to the returned traveling block, whereby the mast can be raised further toward upright position beside the gin pole by pulling the traveling block toward the head of the mast again after removal of said connecting means.

6. In an oil well derrick, the combination with a base, a gin pole mounted thereon, a mast hinged to the base beside the gin pole and extending a considerable distance above it, a traveling block near the top of the mast, an erection line, and means for lowering the elevated traveling block, of sheaves mounted on the gin pole and the back of the mast above the gin pole, said erection line being reeved around said sheaves and having an anchored end behind the mast and a free end extending from the gin pole up into the mast to the traveling block, whereby when the traveling block is lowered to the lower part of the mast the erection line will allow the mast to tilt away from the gin pole into an inclined position, means sup porting the mast from the gin pole in said inclined position while the traveling block is returned to the upper part of the mast, and means for increasing the length of erection line between the gin pole and the traveling block so that the line can be attached to the raised traveling block in the inclined mast, whereby the mast can be lowered further by lowering the traveling block again after removal of said supporting means.

References Cited in the file of this patent UNITED STATES PATENTS 708,625 Danielsen Sept. 9, 1902 1,063,156 Cohen et al May 27, 1913 2,472,359 Woolslayer et al. June 7, 1949 2,570,901 Woolslayer et a1. Oct. 9, 1951 FOREIGN PATENTS 1,014,974 France June 25, 1952 

